In a sunlit Crystal City penthouse, a few dozen transit wonks and software developers pondered a fundamental question: How can technology be used to improve our experience on the roads?

The answers, derived amid a feast of pizza and soda, took various forms.

Mostly, they involved sharing.

A digitally promoted slug line could whisk commuters from Woodbridge to Tysons by making use of high-occupancy vehicle lanes. D.C. commuters headed in similar directions could save time and money by piling into the same car. And car owners could rent out their vehicles to make a little extra money when they weren’t using them.

These were some of the ideas pitched at “Playing with Traffic,” a meetup of coders, entrepreneurs, urban planners and transit professionals and enthusiasts collectively known as “Transportation Techies.”

Fifty transit wonks and tech developers gathered in Crystal City for “Playing with Traffic,” a transit-themed hack night with a focus on driving apps. (Faiz Siddiqui/The Washington Post)

Members of the 1,700-participant group meet monthly at gatherings sponsored by Mobility Lab, the research arm of Arlington County’s commuter services program. The most recent meetup focused on how the sharing economy could improve commuting.

Unlike the door-to-door model popularized by Uber and Lyft, the giants of the industry, true ride sharing “is to try to encourage people to share,” said Larry Filler, bureau chief of Arlington County Commuter Services.

“We have a ground-based system with a lot of seats floating around,” Filler said. “The more you improve the efficiency of the system as a whole, the more there’s opportunity for different choices to be taken. The whole community at large benefits.”

Andriy Klymchuk pitched a modern spin on slugging, the popular form of casual carpooling born in Northern Virginia during the mid-1970s. Klymchuk is one of a dozen people on the team behind Sameride, which aims to pair sluggers and drivers for shared rides to major work destinations.

It’s not the first app to try to digitize the slugging system, but it is different, he said.

“Our major focus is to help to establish new slugging lines,” Klymchuk said.

And, there’s no problem with starting small. Sameride launched on iOS on Thursday with an emphasis on one line, from Woodbridge to Tysons, with the humble goal of attracting 20 or so dedicated commuters to its platform.

“It’s kind of interesting that for start-up companies you don’t take over the world right away,” Michael Schade, Mobility Lab’s senior tech adviser, told the forum. “You start in a certain location.”

Split is another local example.

The app, which launched in 2015 and has more than 100 drivers, is similar to Uber and Lyft, but requires shared rides. Commuters walk to a pickup zone and jump into cars headed to similar destinations — say, with different addresses, but all near McPherson Square in downtown Washington. Riders pay a flat $2 fee plus a dollar per mile.

Anna Petrone, an analyst for the D.C.-based company, began her presentation with a cursory explanation of the app followed by what she called the “full-on nerdy” portion.

She likened Split’s model to a thought experiment: Everyone picks a number from 1 to 100. Those with the same number are grouped together. But compromises are made, like letting numbers within four of one another join the same group, for example — to shrink the pool until it’s been neatly organized into 25 or so groups.

How does this correspond to commuting?

“The likelihood that you’ll get an exact match is not huge,” Petrone said of routes. “But if you add a little bit of variability, you can add them to the same trip.”

Later, Jay Subramaniam pitched Getaround, billing it as “an Airbnb for cars.” (Airbnb allows homeowners to rent out their apartments to tourists and vice versa). The service allows private car owners to rent out their vehicles for a profit, and the carless to swing a set of wheels. It has about 100 registered vehicles in the D.C. region.

“I had no idea anybody had worked out that model,” said Ann Vroom, of Rosslyn, a former attorney. “I was just blown away.”

Transportation researchers lauded the meetup for embracing the ever-growing connection between transit and technology. Stanford Turner, a senior policy analyst for the Eno Center for Transportation, extolled the spirit of “community building.”

“All these different groups, some competing against each other, are all still willing to share and interact,” he said.

Other presenters included Ride Leads, developer of the D.C. Taxi app, and Mapbox, a mapping platform for developers, which demonstrated how to create a ride-sharing app using open maps and data.